Electronic chassis assemblies that generally contain multiple electronics module assemblies made up of circuit card assemblies are known. Such chassis assemblies are used in, for example, military and aircraft applications that may involve harsh environments. Electronic chassis assemblies for such uses can be designed to operate reliably by increasing the ruggedness of the components and/or structure of the assemblies. One way to protect operational reliability and optimize performance is to utilize a system thermal design that manages the significant amount of heat generated by electronic components mounted on circuit cards when operating at high power densities.
There are a variety of known thermal management systems. In some systems, conduction cooling may be used, for example, for up to 200 watts module heat generation. Air-flow-through cooling may be used, for example, for up to 250 watts of module heat generation. Liquid-flow-through cooling may be used, for example, for up to 1000 watts heat generation. These particular thresholds are based on the thermal management system providing a cooling supply to transport the heat to an environmental control system (ECS) using flow materials including air, water, water/alcohol mixtures, and synthetic oils such as poly alpha olefin. The ECS capacity sets the overall system cooling limit. However, electronic modules may be trending toward higher speed and higher performance and generating larger amounts of heat and greater power densities.
It is known to provide a conduction cooled circuit card module where heat generated by the electronic components is absorbed by a thermally conductive cover, forwarded to a module frame and transferred to a module frame-wedge lock interface. The module frame-wedge lock interface functions to dissipate the heat through a chassis rail to which the circuit card modules are mounted. For modern electronic components, the power dissipation values have increased the module power dissipation requirement to the limit of the conduction cooled module frame capacity. Thus, there is a need for a more effective cooling mechanism in order to dissipate such high amounts of heat.